import re

from rest_framework import serializers
from django_redis import get_redis_connection
from rest_framework_jwt.settings import api_settings

from celery_tasks.email.tasks import send_verify_email
from goods.models import SKU
from users.models import User, Address
from .utils import get_user_account


class CreateUserSerializer(serializers.ModelSerializer):
    password2 = serializers.CharField(label="确认密码", write_only=True)
    sms_code = serializers.CharField(label='短信验证码', write_only=True)
    allow = serializers.CharField(label="同意协议", write_only=True)
    
    token = serializers.CharField(label='登录状态token', read_only=True)  # 增加token字段
    
    class Meta:
        model = User
        fields = ('id', 'username', 'password', 'password2', 'sms_code', 'mobile', 'allow', "token")
        extra_kwargs = {
            'username': {
                "min_length": 5,
                "max_length": 20,
                'error_messages': {
                    'min_length': '仅允许5-20个字符的用户名',
                    'max_length': "仅允许5-20个字符的用户名"
                }
            },
            'password': {
                'write_only': True,
                'min_length': 8,
                'max_length': 20,
                'error_messages': {
                    'min_length': '仅允许8-20个字符的密码',
                    'max_length': '仅允许8-20个字符的密码',
                }
            }
        }
    
    def validate_mobile(self, value):
        if not re.match(r'^1[3-9]\d{9}$', value):
            raise serializers.ValidationError('手机号格式错误')
        return value
    
    def validate_allow(self, value):
        if value != 'true':
            raise serializers.ValidationError('请同意用户协议')
        return value
    
    def validate(self, data):
        if data['password'] != data['password2']:
            raise serializers.ValidationError('两次密码不一致')
        
        redis_conn = get_redis_connection('verify_codes')
        mobile = data['mobile']
        real_sms_code = redis_conn.get('sms_%s' % mobile)
        if real_sms_code is None:
            raise serializers.ValidationError('无效的短信验证码')
        
        if data['sms_code'] != real_sms_code.decode():
            raise serializers.ValidationError('短信验证码错误')
        
        return data
    
    def create(self, validated_data):
        
        del validated_data['password2']
        del validated_data['sms_code']
        del validated_data['allow']
        
        user = super().create(validated_data)
        
        user.set_password(validated_data['password'])
        user.save()
        
        jwt_payload_handler = api_settings.JWT_PAYLOAD_HANDLER
        jwt_encode_handler = api_settings.JWT_ENCODE_HANDLER
        
        payload = jwt_payload_handler(user)
        token = jwt_encode_handler(payload)
        
        user.token = token
        return user


class CheckSMSCodeSerializer(serializers.Serializer):
    sms_code = serializers.CharField(min_length=6, max_length=6)
    
    def validate_sms_code(self, value):
        account = self.context['view'].kwargs['account']
        
        user = get_user_account(account)
        if user is None:
            raise serializers.ValidationError('用户不存在')
        
        radis_conn = get_redis_connection('verify_codes')
        real_sms_code = radis_conn.get('sms_%s' % user.mobile)
        if real_sms_code is None:
            raise serializers.ValidationError('无效的短信验证码')
        if value != real_sms_code.decode():
            raise serializers.ValidationError('验证码错误')
        self.user = user
        return value


class RestPasswordSerizalizer(serializers.ModelSerializer):
    password2 = serializers.CharField(label='确认密码', write_only=True)
    access_token = serializers.CharField(label='操作token', write_only=True)
    
    class Meta:
        model = User
        fields = ('id', 'password', 'password2', 'access_token')
        extra_kwargs = {
            'password': {
                'write_only': True,
                'min_length': 8,
                'max_length': 20,
                'error_messages': {
                    'min_length': '仅允许8-20个字符的密码',
                    'max_length': '仅允许8-20个字符的密码',
                }
            }
        }
    
    def validate(self, attrs):
        if attrs['password'] != attrs['password2']:
            raise serializers.ValidationError('两次密码不一致')
        
        allow = User.check_set_password_token(attrs['access_token'], self.context['view'].kwargs.get('pk'))
        if not allow:
            raise serializers.ValidationError("无效的access_token")
        return attrs
    
    def update(self, instance, validated_data):
        
        instance.set_password(validated_data['password'])
        instance.save()
        return instance


class UserDetailSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = ('id', 'username', 'mobile', 'email', 'email_active')


class EmailSerizlizer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = ('id', 'email')
        extra_kwargs = {
            'email': {
                'required': True
            }
        }
    
    def update(self, instance, validate_data):
        email = validate_data.get("email")
        instance.email = email
        instance.save()
        
        verify_url = instance.generate_verify_email_url()
        send_verify_email(email, verify_url)
        return instance


class UserAddressSerizlizer(serializers.ModelSerializer):
    province = serializers.StringRelatedField(read_only=True)
    city = serializers.StringRelatedField(read_only=True)
    district = serializers.StringRelatedField(read_only=True)
    province_id = serializers.IntegerField(label='省ID', required=True)
    city_id = serializers.IntegerField(label='市ID', required=True)
    district_id = serializers.IntegerField(label='区ID', required=True)
    
    class Meta:
        model = Address
        exclude = ('user', 'is_deleted', 'create_time', 'update_time')
    
    def validate_mobile(self, value):
        if not re.match(r'^1[3-9]\d{9}$', value):
            raise serializers.ValidationError('手机号格式错误')
        return value
    
    def create(self, validated_data):
        validated_data['user'] = self.context['request'].user
        return super().create(validated_data)
    
class AddressTitleSerializer(serializers.ModelSerializer):
    """
    地址标题
    """
    class Meta:
        model = Address
        fields = ('title',)

from . import constants
class AddUserBrowsingHistorySerializer(serializers.Serializer):
    sku_id = serializers.IntegerField(label="商品SKU编号", min_value=1, required=True)
    def valite_sku_id(self,value):
        try:
            SKU.objects.get(id=value)
        except SKU.DoesNotExist:
            raise  serializers.ValidationError('该商品不存在')
        return value
    
    def create(self, validated_data):
        user_id = self.context['request'].user.id
        sku_id = validated_data['sku_id']
        redis_conn = get_redis_connection('history')

        # 移除已经存在的本商品浏览记录
        redis_conn.lrem("history_%s" % user_id, 0, sku_id)
        # 添加新的浏览记录
        redis_conn.lpush("history_%s" % user_id, sku_id)
        # 只保存最多5条记录
        redis_conn.ltrim("history_%s" % user_id, 0, constants.USER_BROWSING_HISTORY_COUNTS_LIMIT - 1)

        return validated_data